12-12-2013 дата публикации
Номер: US20130326850A1
Принадлежит:
A burning-free and non-cyanide method for recycling waste printed circuit board is provided, comprising the following steps: desoldering to separate lead and tin; crashing and electrostatic selecting to respectively extract stibium, aluminum, copper, nickel, silver, gold, platinum and palladium. The method can realize the maximization of recycling of valuable metal resources, can thoroughly separate the metal lead and tin for recycling, and meanwhile increase the recycling rate of the metal palladium. 1. A burning-free and non-cyanide method for recycling waste printed circuit board , comprising:(1) desoldering treatment: providing waste printed circuit board, washing, drying, immersing in nitric acid type stripping solution for desoldering treatment, after the desoldering treatment, said waste printed circuit board proceeds to step (3), spent stripping solution thereof proceeds to step (2);{'sup': 3+', '4+, '(2) separation of lead and tin: providing said spent stripping solution from step (1), stirring under a temperature in a range of from 60° C. to 95° C., adding oxidant, regulating pH to from 2.5 to 3.0 by adding alkali, reacting for from 1 to 3 h to precipitate Feand Snwhile leaving lead ions and copper ions remaining in solution, filtering and separating solid and liquid, obtaining tin-containing residues and lead-containing filtrate, recycling tin and lead respectively;'}(3) crush and electrostatic separation: providing said desoldering treated circuit board from step (1), drying, crushing roughly, eddy current separating, crushing finely and electrostatic separating, removing robber and plastic materials, obtaining metal-rich part powders;{'sub': 2', '3', '2', '3', '2, '(4) extraction of lead, antimony and aluminium: providing said metal-rich part powders from step (3), leaching Pb ions, Sb ions and Al ions, filtering, evaporating and concentrating filtrate to obtain mixed crystals of NaPbO, NaSbOand NaAlO, evaporating mother liquor to return back for water ...
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